Did you mean that can CRISPR/Cas9 distinguish two target DNA sequences which have only 1-bp (SNP) difference? Probably very difficult (it might cut both sequences).

Have you seen this paper: "Distinguishing SNPs with CRISPR/Cas"

http://www.biotechniques.com/news/Distinguishing-SNPs-with-CRISPRCas/biotechniques-364885.html

However, if this single nucleotide mutation or the SNP leads to the forming of  a novel protospacer adjacent motif (PAM), then CRISPR/Cas9 should be able to distinguish this PAM-containing allele from other alleles.

See the attached paper: CRISPR/Cas9 DNA cleavage at SNP-derived PAM enables both in vitro and in vivo KRT12 mutation-specific targeting